Commit 42619747 authored by Ira Weiny's avatar Ira Weiny Committed by Dave Jiang
Browse files

printf: Add print format (%pra) for struct range 

The use of struct range in the CXL subsystem is growing.  In particular,
the addition of Dynamic Capacity devices uses struct range in a number
of places which are reported in debug and error messages.

To wit requiring the printing of the start/end fields in each print
became cumbersome.  Dan Williams mentions in [1] that it might be time
to have a print specifier for struct range similar to struct resource.

A few alternatives were considered including '%par', '%r', and '%pn'.
%pra follows that struct range is similar to struct resource (%p[rR])
but needs to be different.  Based on discussions with Petr and Andy
'%pra' was chosen.[2]

Andy also suggested to keep the range prints similar to struct resource
though combined code.  Add hex_range() to handle printing for both
pointer types.

Finally introduce DEFINE_RANGE() as a parallel to DEFINE_RES_*() and use
it in the tests.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: open list <linux-kernel@vger.kernel.org>
Link: https://lore.kernel.org/all/663922b475e50_d54d72945b@dwillia2-xfh.jf.intel.com.notmuch/ [1]
Link: https://lore.kernel.org/all/66cea3bf3332f_f937b29424@iweiny-mobl.notmuch/

 [2]
Suggested-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarIra Weiny <ira.weiny@intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20241025-cxl-pra-v2-3-123a825daba2@intel.com


Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
parent 3dff66ff

Documentation/core-api/printk-formats.rst

+13 −0
Original line number Diff line number Diff line
@@ -236,6 +236,19 @@ width of the CPU data path. 


Passed by reference.



Struct Range

------------



::



	%pra    [range 0x0000000060000000-0x000000006fffffff] or

		[range 0x0000000060000000]



For printing struct range.  struct range holds an arbitrary range of u64

values.  If start is equal to end only print the start value.



Passed by reference.



DMA address types dma_addr_t

----------------------------

include/linux/range.h

+6 −0
Original line number Diff line number Diff line
@@ -31,4 +31,10 @@ int clean_sort_range(struct range *range, int az); 


void sort_range(struct range *range, int nr_range);



#define DEFINE_RANGE(_start, _end)		\

(struct range) {				\

		.start = (_start),		\

		.end = (_end),			\

	}



#endif

lib/test_printf.c

+17 −0
Original line number Diff line number Diff line
@@ -432,6 +432,22 @@ struct_resource(void) 
	     "%pR", &test_resource);

}



static void __init

struct_range(void)

{

	struct range test_range = DEFINE_RANGE(0xc0ffee00ba5eba11,

					       0xc0ffee00ba5eba11);

	test("[range 0xc0ffee00ba5eba11]", "%pra", &test_range);



	test_range = DEFINE_RANGE(0xc0ffee, 0xba5eba11);

	test("[range 0x0000000000c0ffee-0x00000000ba5eba11]",

	     "%pra", &test_range);



	test_range = DEFINE_RANGE(0xba5eba11, 0xc0ffee);

	test("[range 0x00000000ba5eba11-0x0000000000c0ffee]",

	     "%pra", &test_range);

}



static void __init

addr(void)

{
@@ -807,6 +823,7 @@ test_pointer(void) 
	symbol_ptr();

	kernel_ptr();

	struct_resource();

	struct_range();

	addr();

	escaped_str();

	hex_string();

lib/vsprintf.c

+51 −6
Original line number Diff line number Diff line
@@ -1039,6 +1039,20 @@ static const struct printf_spec default_dec04_spec = { 
	.flags = ZEROPAD,

};



static noinline_for_stack

char *hex_range(char *buf, char *end, u64 start_val, u64 end_val,

		struct printf_spec spec)

{

	buf = number(buf, end, start_val, spec);

	if (start_val == end_val)

		return buf;



	if (buf < end)

		*buf = '-';

	++buf;

	return number(buf, end, end_val, spec);

}



static noinline_for_stack

char *resource_string(char *buf, char *end, struct resource *res,

		      struct printf_spec spec, const char *fmt)
@@ -1115,11 +1129,7 @@ char *resource_string(char *buf, char *end, struct resource *res, 
		p = string_nocheck(p, pend, "size ", str_spec);

		p = number(p, pend, resource_size(res), *specp);

	} else {

		p = number(p, pend, res->start, *specp);

		if (res->start != res->end) {

			*p++ = '-';

			p = number(p, pend, res->end, *specp);

		}

		p = hex_range(p, pend, res->start, res->end, *specp);

	}

	if (decode) {

		if (res->flags & IORESOURCE_MEM_64)
@@ -1140,6 +1150,31 @@ char *resource_string(char *buf, char *end, struct resource *res, 
	return string_nocheck(buf, end, sym, spec);

}



static noinline_for_stack

char *range_string(char *buf, char *end, const struct range *range,

		   struct printf_spec spec, const char *fmt)

{

	char sym[sizeof("[range 0x0123456789abcdef-0x0123456789abcdef]")];

	char *p = sym, *pend = sym + sizeof(sym);



	struct printf_spec range_spec = {

		.field_width = 2 + 2 * sizeof(range->start), /* 0x + 2 * 8 */

		.flags = SPECIAL | SMALL | ZEROPAD,

		.base = 16,

		.precision = -1,

	};



	if (check_pointer(&buf, end, range, spec))

		return buf;



	p = string_nocheck(p, pend, "[range ", default_str_spec);

	p = hex_range(p, pend, range->start, range->end, range_spec);

	*p++ = ']';

	*p = '\0';



	return string_nocheck(buf, end, sym, spec);

}



static noinline_for_stack

char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,

		 const char *fmt)
@@ -2229,6 +2264,15 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, 
	return widen_string(buf, buf - buf_start, end, spec);

}



static noinline_for_stack

char *resource_or_range(const char *fmt, char *buf, char *end, void *ptr,

			struct printf_spec spec)

{

	if (*fmt == 'r' && fmt[1] == 'a')

		return range_string(buf, end, ptr, spec, fmt);

	return resource_string(buf, end, ptr, spec, fmt);

}



int __init no_hash_pointers_enable(char *str)

{

	if (no_hash_pointers)
@@ -2277,6 +2321,7 @@ char *rust_fmt_argument(char *buf, char *end, void *ptr); 
 * - 'Bb' as above with module build ID (for use in backtraces)

 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]

 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]

 * - 'ra' For struct ranges, e.g., [range 0x0000000000000000 - 0x00000000000000ff]

 * - 'b[l]' For a bitmap, the number of bits is determined by the field

 *       width which must be explicitly specified either as part of the

 *       format string '%32b[l]' or through '%*b[l]', [l] selects
@@ -2401,7 +2446,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, 
		return symbol_string(buf, end, ptr, spec, fmt);

	case 'R':

	case 'r':

		return resource_string(buf, end, ptr, spec, fmt);

		return resource_or_range(fmt, buf, end, ptr, spec);

	case 'h':

		return hex_string(buf, end, ptr, spec, fmt);

	case 'b':